From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [patch V2 01/29] tracing: Cleanup stack trace code Date: Thu, 18 Apr 2019 18:19:38 -0400 Message-ID: <20190418181938.2e2a9a04@gandalf.local.home> References: <20190418084119.056416939@linutronix.de> <20190418084253.142712304@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190418084253.142712304@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org To: Thomas Gleixner Cc: LKML , Josh Poimboeuf , x86@kernel.org, Andy Lutomirski , Alexander Potapenko , Alexey Dobriyan , Andrew Morton , Pekka Enberg , linux-mm@kvack.org, David Rientjes , Christoph Lameter , Catalin Marinas , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Mike Rapoport , Akinobu Mita , iommu@lists.linux-foundation.org, Robin Murphy , Christoph Hellwig , Marek Szyprowski List-Id: linux-arch.vger.kernel.org On Thu, 18 Apr 2019 10:41:20 +0200 Thomas Gleixner wrote: > @@ -412,23 +404,20 @@ stack_trace_sysctl(struct ctl_table *tab > void __user *buffer, size_t *lenp, > loff_t *ppos) > { > - int ret; > + int ret, was_enabled; One small nit. Could this be: int was_enabled; int ret; I prefer only joining variables that are related on the same line. Makes it look cleaner IMO. > > mutex_lock(&stack_sysctl_mutex); > + was_enabled = !!stack_tracer_enabled; > Bah, not sure why I didn't do it this way to begin with. I think I copied something else that couldn't do it this way for some reason and didn't put any brain power behind the copy. :-/ But that was back in 2008 so I blame it on being "young and stupid" ;-) Other then the above nit and removing the unneeded +1 in max_entries: Reviewed-by: Steven Rostedt (VMware) -- Steve > ret = proc_dointvec(table, write, buffer, lenp, ppos); > > - if (ret || !write || > - (last_stack_tracer_enabled == !!stack_tracer_enabled)) > + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) > goto out; > > - last_stack_tracer_enabled = !!stack_tracer_enabled; > - > if (stack_tracer_enabled) > register_ftrace_function(&trace_ops); > else > unregister_ftrace_function(&trace_ops); > - > out: > mutex_unlock(&stack_sysctl_mutex); > return ret; > @@ -444,7 +433,6 @@ static __init int enable_stacktrace(char > strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); > > stack_tracer_enabled = 1; > - last_stack_tracer_enabled = 1; > return 1; > } > __setup("stacktrace", enable_stacktrace); > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:36492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725853AbfDRWTp (ORCPT ); Thu, 18 Apr 2019 18:19:45 -0400 Date: Thu, 18 Apr 2019 18:19:38 -0400 From: Steven Rostedt Subject: Re: [patch V2 01/29] tracing: Cleanup stack trace code Message-ID: <20190418181938.2e2a9a04@gandalf.local.home> In-Reply-To: <20190418084253.142712304@linutronix.de> References: <20190418084119.056416939@linutronix.de> <20190418084253.142712304@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Thomas Gleixner Cc: LKML , Josh Poimboeuf , x86@kernel.org, Andy Lutomirski , Alexander Potapenko , Alexey Dobriyan , Andrew Morton , Pekka Enberg , linux-mm@kvack.org, David Rientjes , Christoph Lameter , Catalin Marinas , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Mike Rapoport , Akinobu Mita , iommu@lists.linux-foundation.org, Robin Murphy , Christoph Hellwig , Marek Szyprowski , Johannes Thumshirn , David Sterba , Chris Mason , Josef Bacik , linux-btrfs@vger.kernel.org, dm-devel@redhat.com, Mike Snitzer , Alasdair Kergon , intel-gfx@lists.freedesktop.org, Joonas Lahtinen , Maarten Lankhorst , dri-devel@lists.freedesktop.org, David Airlie , Jani Nikula , Daniel Vetter , Rodrigo Vivi , linux-arch@vger.kernel.org Message-ID: <20190418221938.ad5z16BpHwk5ZqDtDECISgwVvP7-XyDhxJLu3P4zZio@z> On Thu, 18 Apr 2019 10:41:20 +0200 Thomas Gleixner wrote: > @@ -412,23 +404,20 @@ stack_trace_sysctl(struct ctl_table *tab > void __user *buffer, size_t *lenp, > loff_t *ppos) > { > - int ret; > + int ret, was_enabled; One small nit. Could this be: int was_enabled; int ret; I prefer only joining variables that are related on the same line. Makes it look cleaner IMO. > > mutex_lock(&stack_sysctl_mutex); > + was_enabled = !!stack_tracer_enabled; > Bah, not sure why I didn't do it this way to begin with. I think I copied something else that couldn't do it this way for some reason and didn't put any brain power behind the copy. :-/ But that was back in 2008 so I blame it on being "young and stupid" ;-) Other then the above nit and removing the unneeded +1 in max_entries: Reviewed-by: Steven Rostedt (VMware) -- Steve > ret = proc_dointvec(table, write, buffer, lenp, ppos); > > - if (ret || !write || > - (last_stack_tracer_enabled == !!stack_tracer_enabled)) > + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) > goto out; > > - last_stack_tracer_enabled = !!stack_tracer_enabled; > - > if (stack_tracer_enabled) > register_ftrace_function(&trace_ops); > else > unregister_ftrace_function(&trace_ops); > - > out: > mutex_unlock(&stack_sysctl_mutex); > return ret; > @@ -444,7 +433,6 @@ static __init int enable_stacktrace(char > strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); > > stack_tracer_enabled = 1; > - last_stack_tracer_enabled = 1; > return 1; > } > __setup("stacktrace", enable_stacktrace); >